[llvm] [Coroutines] Avoid repeated hash lookups (NFC) (PR #127956)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-transforms

Author: Kazu Hirata (kazutakahirata)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/127956.diff


1 Files Affected:

- (modified) llvm/lib/Transforms/Coroutines/MaterializationUtils.cpp (+3-2) 


``````````diff
diff --git a/llvm/lib/Transforms/Coroutines/MaterializationUtils.cpp b/llvm/lib/Transforms/Coroutines/MaterializationUtils.cpp
index 5021425152f6c..6aaabca95c4c3 100644
--- a/llvm/lib/Transforms/Coroutines/MaterializationUtils.cpp
+++ b/llvm/lib/Transforms/Coroutines/MaterializationUtils.cpp
@@ -293,7 +293,8 @@ void coro::doRematerializations(
     for (Instruction *U : E.second) {
       // Don't process a user twice (this can happen if the instruction uses
       // more than one rematerializable def)
-      if (AllRemats.count(U))
+      auto [It, Inserted] = AllRemats.try_emplace(U);
+      if (!Inserted)
         continue;
 
       // Constructor creates the whole RematGraph for the given Use
@@ -306,7 +307,7 @@ void coro::doRematerializations(
                       ++I) { (*I)->Node->dump(); } dbgs()
                  << "\n";);
 
-      AllRemats[U] = std::move(RematUPtr);
+      It->second = std::move(RematUPtr);
     }
   }
 

``````````

</details>


https://github.com/llvm/llvm-project/pull/127956